crypto: octeontx2 - Avoid stack variable overflow

Building with -Warray-bounds showed a stack variable array index
overflow. Increase the expected size of the array to avoid the warning:

In file included from ./include/linux/printk.h:555,
                 from ./include/asm-generic/bug.h:22,
                 from ./arch/x86/include/asm/bug.h:84,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/mmdebug.h:5,
                 from ./include/linux/gfp.h:5,
                 from ./include/linux/firmware.h:7,
                 from drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c:5:
drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c: In function 'otx2_cpt_print_uc_dbg_info':
./include/linux/dynamic_debug.h:162:33: warning: array subscript 4 is above array bounds of 'u32[4]' {aka 'unsigned int[4]'} [-Warray-bounds]
  162 |         _dynamic_func_call(fmt, __dynamic_pr_debug,             \
      |                                 ^
./include/linux/dynamic_debug.h:134:17: note: in definition of macro '__dynamic_func_call'
  134 |                 func(&id, ##__VA_ARGS__);               \
      |                 ^~~~
./include/linux/dynamic_debug.h:162:9: note: in expansion of macro '_dynamic_func_call'
  162 |         _dynamic_func_call(fmt, __dynamic_pr_debug,             \
      |         ^~~~~~~~~~~~~~~~~~
./include/linux/printk.h:570:9: note: in expansion of macro 'dynamic_pr_debug'
  570 |         dynamic_pr_debug(fmt, ##__VA_ARGS__)
      |         ^~~~~~~~~~~~~~~~
drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c:1807:41: note: in expansion of macro 'pr_debug'
 1807 |                                         pr_debug("Mask: %8.8x %8.8x %8.8x %8.8x %8.8x",
      |                                         ^~~~~~~~
drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c:1765:13: note: while referencing 'mask'
 1765 |         u32 mask[4];
      |             ^~~~

This is justified because the mask size (eng_grps->engs_num) can be at
most 144 (OTX2_CPT_MAX_ENGINES bits), which is larger than available
storage. 4 * 32 == 128, so this must be 5: 5 * 32bit = 160.

Additionally clear the mask before conversion so trailing bits are zero.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Arnaud Ebalard <arno@natisbad.org>
Cc: Srujana Challa <schalla@marvell.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Suheil Chandran <schandran@marvell.com>
Cc: Shijith Thotton <sthotton@marvell.com>
Cc: Lukasz Bartosik <lbartosik@marvell.com>
Cc: linux-crypto@vger.kernel.org
Fixes: d9d77497 ("crypto: octeontx2 - add apis for custom engine groups")
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>